A pseudo-outbreak of nosocomial infections associated with the introduction of an antibiotic management programme

Area of Science:

• Infectious Disease Epidemiology
• Hospital Quality Improvement
• Antimicrobial Stewardship

Background:

• Nosocomial infections (NIs) represent a significant healthcare challenge.
• A university hospital observed a sudden, sustained 30% increase in NI rates.
• This increase followed a period of stable infection rates.

Purpose of the Study:

• To investigate the cause of the apparent surge in nosocomial infections.
• To differentiate between a true outbreak and a pseudo-outbreak.
• To evaluate the impact of an antibiotic management program on infection reporting.

Main Methods:

• Comparative analysis of demographic data, risk factors, and case features between endemic and epidemic periods.
• Review of hospital policy and procedure changes.
• Outbreak investigation including surveillance data and clinical criteria assessment.

Main Results:

• No evidence of a true nosocomial infection outbreak was found.
• The apparent increase coincided with the start of an antibiotic management program.
• A shift in reporting occurred, with surveillance nurses relying more on physician diagnosis than specific clinical criteria.

Conclusions:

• The observed rise in nosocomial infections was a pseudo-outbreak, driven by altered documentation practices.
• Clinicians modified reporting thresholds to justify antibiotic prescribing post-implementation of the management program.
• This highlights the importance of standardized criteria in infection surveillance and antimicrobial stewardship.